In the metal industry, such as the aluminum industry, liquid metal is transferred from a location to another using heated trough or launder having a general U-shape cross-section, and including a castable refractory. An example of a prior art launder section 1 is shown in FIG. 1. The refractory 2 is contained in a steel support 8 having a similar U-shape. Insulating layer(s) 4 are placed around the refractory to help maintaining the temperature of the liquid metal and to limit heat losses by conduction. The troughs are usually pre-heated using hot air blowers, gas burners, or heated covers. Heated covers are most commonly provided with electrical heating elements. Heating panels 6 can also be located on the side of each sidewall of the refractory 2, as best shown in FIG. 1A.
Examples of such installations are described in patent applications WO 2004/082867 and US 2010/0109210 pertaining to the Applicant. While efficient, one drawback of the side-mounted heating troughs is that they are subject to infiltrations of liquid metal. In addition, their maintenance and replacement can be difficult. Heated covers are subject to metal splashing and mechanical abuse, shortening their useful life. Existing heated covers or side-mounted heating panels also tend to be rather cumbersome and expensive.
In light of the above, there is a need for improved devices that allow to maintain molten metal in a liquid state, and that also allow to be operated, maintained, and/or replaced in a simpler fashion. It would also be desirable if such devices or method had a lower cost than existing devices while remaining relatively easy to manufacture.